The springs and the bore are the most important.
Regarding the bore, there is an excellent example. This one:
http://www.gunbroker.com/Auction/Vie...Item=513564050
It's obviously not German, but buyer did not know that. He bought it, and found the bore is not ideal. Got angry:
"513564050
F Misrepresented the C96 I bought. Said it was a good shooter and had a good bore. Said on phone that it was a German Mauser. Was actually Chinese with terrible bore and ruined chamber. Don't trust him
Response: (left on 12/4/2015) Bought a $700 Mausher that only needs cleaning. Mauser address on pistol. Disgruntled! Select
tdh4570 A+(9)
Seller 11/30/2015 10:58 AM"
Seller suggested buyer to clean it... but the darn thing has already been cleaned into silver bright. The buyer definitely needs Redman or Closet service.